so he has to not look defensive. >> pelley: john, thank you very much. we'll be back later tonight with cbs news live coverage of the debate. that's 9:00 eastern time and 6:00 in the west. today secretary of state hillary clinton promised a full and open investigation into the terror attack on the u.s. consulate in benghazi, libya, three weeks ago. four americans, you'll recall, were killed, including ambassador chris stevens. there are a lot of questions about what happened. margaret brennan has been following this story and she's at the start tonight. margaret? >> reporter: good evening, scott. the cretary of state reacted to pressure from the public, the press, and the house oversight committee to address the controversy around the administration's response to that attack on the u.s. consulate in benghazi. were there multiple requests for increased security in tripoli and benghazi and can you address whether washington or your office rejected those requests? >> well, let me start by cautioning everyone against seizing on any single statement or piece